Sham lens and electronic device

Abstract

The present disclosure belongs to the technical field of optics, and particularly relates to a Schmidt lens and an electronic device. The Schmidt lens disclosed by the present disclosure comprises seven lenses coaxially arranged in sequence from the object side to the image side, and the number is relatively small, which is conducive to reducing the cost. The incident surface of the first lens is a concave surface, which can converge the off-axis light beams with a large angle, and can also reduce the light path aperture, thereby realizing the miniaturization of the optical path structure. It can also make the imaging of a large target surface be met under the limitation of ensuring the overall size of the lens. An aperture stop is arranged between the third lens and the fourth lens, and the incident surface of the fourth lens towards the aperture stop is a concave surface, which is conducive to reducing the angle of light incident to the lens surface, correcting the system aberration, and improving the imaging effect of the Schmidt lens. The difference between the refractive indexes of at least two lenses of the seven lenses is less than or equal to 0.1, so that the change amount of the refractive indexes of the at least two lenses is small when the temperature changes, so that the Schmidt lens has a low temperature drift characteristic.

Description

Technical Field

[0001] This disclosure relates to the field of optical technology, and more particularly to a SAM lens and electronic device. Background Technology

[0002] With the development of image processing and computer technology, machine vision technology has become widely used due to its advantages such as high precision, high speed, and high stability. Among them, the Scham lens, which utilizes Scham's law for imaging, can clearly image the entire field of view of an oblique target, which is beneficial for expanding the clear range and improving measurement accuracy when used in industrial measurement.

[0003] In related technologies, large-area image sensors have significant advantages in high-precision measurement and complex scene applications. Therefore, it is particularly important to design low-cost, high-imaging-performance lenses while maintaining a large image sensor size. Summary of the Invention

[0004] This disclosure provides a SAM lens and electronic device, which, based on a large-area photosensitive element, features low cost and low temperature drift.

[0005] To achieve the above objectives, the present disclosure adopts the following technical solution:

[0006] The first aspect of this disclosure provides a SAM lens, comprising: a first lens, a second lens, a third lens, a fourth lens, a fifth lens, a sixth lens, and a seventh lens arranged coaxially from the object side to the image side; wherein the fourth lens and the fifth lens are cemented lenses; and the incident surface of the first lens is concave.

[0007] An aperture stop is provided between the third lens and the fourth lens, and the ingress surface of the fourth lens facing the aperture stop is concave.

[0008] The difference in refractive index of at least two of the seven lenses in the Sham lens is less than or equal to 0.1.

[0009] The first lens has negative optical power, the second lens has positive optical power, the third lens has negative optical power, the fourth lens has negative optical power, the fifth lens has positive optical power, the sixth lens has negative optical power, and the seventh lens has positive optical power.

[0010] Compared with the prior art, the Sham lens provided by the first aspect of this disclosure has the following advantages:

[0011] The SAM lens disclosed herein includes: a first lens, a second lens, a third lens, a fourth lens, a fifth lens, a sixth lens, and a seventh lens arranged coaxially from the object side to the image side. The relatively small number of lenses helps reduce costs. The first lens has a concave incident surface, which can converge off-axis beams at large angles while reducing the light path aperture, thus miniaturizing the optical path structure. This also allows for imaging of large target surfaces while maintaining the overall size of the lens. An aperture stop is provided between the third and fourth lenses. The fourth lens has a concave incident surface facing the aperture stop, causing the side of the fourth lens closest to the aperture stop to bend towards it. This helps reduce the angle at which light enters the lens surface, correcting system aberrations and improving the imaging effect of the SAM lens. The difference in refractive index between at least two of the seven lenses is less than or equal to 0.1, ensuring that the refractive index of at least two lenses changes little with temperature variations, thus having a smaller impact on imaging performance and effectively controlling the low-temperature drift of the SAM lens.

[0012] As an improvement to the Sham lens disclosed herein, the refractive index difference between any two of the third lens, the fourth lens, and the seventh lens is less than or equal to 0.05.

[0013] As an improvement to the Sham lens described above in this disclosure, the Abbe number difference between the fourth lens and the fifth lens is greater than 20.

[0014] As an improvement to the SAM lens disclosed herein, the focal length f1 of the first lens is -435mm to -345mm; the focal length f2 of the second lens is 35mm to 45mm; the focal length f3 of the third lens is -2660mm to -2120mm; the focal length f4 of the fourth lens is -25mm to -19mm; the focal length f5 of the fifth lens is 60mm to 76mm; the focal length f6 of the sixth lens is -55mm to -43mm; and the focal length f7 of the seventh lens is 23mm to 30mm.

[0015] As an improvement to the Sham lens disclosed herein, the first lens is a concave-convex lens, the second lens is a biconvex lens, the third lens is a convex-concave lens, the fourth lens is a biconcave lens, the fifth lens is a biconvex lens, the sixth lens is a concave-convex lens, and the seventh lens is a biconvex lens.

[0016] As an improvement to the Sham lens disclosed herein, the radius of curvature R11 of the incident surface of the first lens is -33mm to -26mm, and the radius of curvature R12 of the exit surface is -38mm to -30mm; the radius of curvature R21 of the incident surface of the second lens is 31mm to 39mm, and the radius of curvature R22 of the exit surface is -180mm to -143mm; the radius of curvature R31 of the incident surface of the third lens is 12mm to 16mm, and the radius of curvature R32 of the exit surface is 10mm to 13mm; the radius of curvature R41 of the incident surface of the fourth lens is... The radius of curvature of the incident surface of the fifth lens is -28mm to -22mm, and the radius of curvature of the exit surface R42 is 9mm to 13mm; the radius of curvature of the incident surface of the sixth lens is -12mm to -9mm, and the radius of curvature of the exit surface R62 is -23mm to -17mm; the radius of curvature of the incident surface of the seventh lens is 655mm to 820mm, and the radius of curvature of the exit surface R72 is -26mm to -21mm.

[0017] As an improvement to the SAM lens disclosed herein, the center thickness GT1 of the first lens is 1.9 mm to 2.5 mm; the center thickness GT2 of the second lens is 2.4 mm to 3.1 mm; the center thickness GT3 of the third lens is 5.3 mm to 6.7 mm; the center thickness GT4 of the fourth lens is 1.3 mm to 1.7 mm; the center thickness GT5 of the fifth lens is 4.5 mm to 5.7 mm; the center thickness GT6 of the sixth lens is 1.9 mm to 2.5 mm; and the center thickness GT7 of the seventh lens is 4.0 mm to 5.1 mm.

[0018] As an improvement to the Sham lens disclosed herein, the air gap distance AT1 between the first lens and the second lens along the optical axis is 0.07 mm to 0.11 mm; the air gap distance AT2 between the second lens and the third lens along the optical axis is 0.07 mm to 0.11 mm; the air gap distance AT3 between the third lens and the aperture stop along the optical axis is 2.35 mm to 3.00 mm; the air gap distance AT4 between the aperture stop and the fourth lens along the optical axis is 5.95 mm to 7.50 mm; the fourth lens and the fifth lens are cemented lenses; the air gap distance AT5 between the fifth lens and the sixth lens along the optical axis is 4.20 mm to 5.30 mm; the air gap distance AT6 between the sixth lens and the seventh lens along the optical axis is 0.07 mm to 0.11 mm; and the air gap distance BFL between the seventh lens and the image plane along the optical axis is 20.65 mm to 25.90 mm.

[0019] As an improvement to the SAM lens disclosed herein, the focal length f1 of the first lens and the focal length f of the SAM lens satisfy 7 < |f1 / f| < 10.9; the focal length f2 of the second lens and the focal length f of the SAM lens satisfy 0.7 < f2 / f < 1.2; the focal length f3 of the third lens and the focal length f of the SAM lens satisfy 53 < |f3 / f| < 66.5; the focal length f4 of the fourth lens and the focal length f of the SAM lens satisfy 0.3 < |f4 / f| < 0.7; the focal length f5 of the fifth lens and the focal length f of the SAM lens satisfy 1.2 < f5 / f < 1.9; the focal length f6 of the sixth lens and the focal length f of the SAM lens satisfy 0.8 < |f6 / f| < 1.4; and the focal length f7 of the seventh lens and the focal length f of the SAM lens satisfy 0.4 < f7 / f < 0.8.

[0020] As an improvement to the Sham lens disclosed herein, the first lens has a refractive index N1 of 1.65–1.7 and an Abbe number V1 of 47–47.5; the second lens has a refractive index N2 of 1.67–1.72 and an Abbe number V2 of 56–56.5; the third lens has a refractive index N3 of 1.8–1.85 and an Abbe number V3 of 42.5–43; the fourth lens has a refractive index N4 of 1.8–1.85 and an Abbe number V4 of 25.2–25.7; the fifth lens has a refractive index N5 of 1.7–1.75 and an Abbe number V5 of 50–50.5; the sixth lens has a refractive index N6 of 1.47–1.52 and an Abbe number V6 of 62–62.5; and the seventh lens has a refractive index N7 of 1.8–1.85 and an Abbe number V7 of 25.2–25.7.

[0021] As an improvement to the Sham lens disclosed herein, the radius of curvature R41 of the incident surface of the fourth lens and the radius of curvature R52 of the exit surface of the fifth lens satisfy 0.7 < R41 / R52 < 1.1; the center thickness GT4 of the fourth lens and the center thickness GT5 of the fifth lens satisfy 0.2 < GT4 / GT5 < 0.4; the Abbe number V4 of the fourth lens and the Abbe number V5 of the fifth lens satisfy 24.3 < |V4 - V5| < 25.3.

[0022] As an improvement to the aforementioned SAM lens disclosed herein, the SAM lens has a focal length of 40mm to 60mm; an aperture of F2.5 to 3.5; a field of view (FOV) of 60mm to 130mm; a working distance (WD) of 210mm to 270mm; an angle α between the optical axis of the SAM lens and the target plane of 18° to 25°; a working wavelength (WL) of 400nm to 480nm; and a magnification of -0.206.

[0023] As an improvement to the SAM lens disclosed herein, the first lens, the second lens, and the third lens form a first lens group, the focal length fa of the first lens group being 30mm to 50mm; the fourth lens and the fifth lens form a second lens group, the focal length fb of the second lens group being -75mm to -55mm; the sixth lens and the seventh lens form a third lens group, the focal length fc of the third lens group being 40mm to 60mm; the axial distance between the first lens group and the second lens group is 9mm to 11mm; the axial distance between the second lens group and the third lens group is 4mm to 6mm.

[0024] As an improvement to the SAM lens disclosed herein, the focal length fa of the first lens group and the focal length f of the SAM lens satisfy 1 < fa / f < 1.7; the focal length fb of the second lens group and the focal length f of the SAM lens satisfy 1 < |fb / f| < 1.8; the focal length fc of the third lens group and the focal length f of the SAM lens satisfy 0.8 < fc / f < 1.4; the axial distance d12 between the first lens group and the second lens group and the axial distance d23 between the second lens group and the third lens group satisfy 1.7 < d12 / d23 < 2.4.

[0025] As an improvement to the SAM lens disclosed herein, after focusing at 25°C, the modulation transfer function of each field of view has a contrast greater than 0.5 at a spatial frequency of 60 line pairs / mm; after imaging at -10°C to 60°C, the contrast attenuation of the modulation transfer function of each field of view at a spatial frequency of 60 line pairs / mm is less than 0.1; after focusing at 25°C, the field astigmatism value of the corresponding coaxial optical path full field of view is less than 0.2mm; the distortion value of the corresponding coaxial optical path full field of view is less than 0.2%; and after imaging at -10°C to 60°C, the change in field astigmatism value of the corresponding coaxial optical path full field of view is less than 0.05mm.

[0026] As an improvement to the SAM lens disclosed herein, after focusing at 25°C, the modulation transfer function of each field of view in the defocus state has the maximum contrast when the back focus displacement is 0, and the contrast is greater than 0.5; after imaging at -10°C to 60°C, the absolute value of the back focus displacement change corresponding to the maximum contrast value of the modulation transfer function of each field of view in the defocus state is less than 0.01.

[0027] As an improvement to the SAM lens disclosed herein, each lens element of the SAM lens is a glass lens, and each lens element of the SAM lens is a spherical lens.

[0028] A second aspect of this disclosure provides an electronic device that includes the Sham lens described in the first aspect.

[0029] The electronic device provided in the second aspect of this disclosure, since it includes the SAM lens described in the first aspect, also has the same advantages as the SAM lens described in the first aspect.

[0030] As an improvement to the electronic device described in this disclosure, the electronic device is a camera. Attached Figure Description

[0031] To more clearly illustrate the technical solutions in the embodiments of this disclosure or the prior art, the accompanying drawings used in the description of the embodiments of this disclosure or the prior art will be briefly introduced below. Obviously, the accompanying drawings described below are only a part of the embodiments of this disclosure. These drawings and text descriptions are not intended to limit the scope of the concept of this disclosure in any way, but to illustrate the concept of this disclosure to those skilled in the art by referring to specific embodiments. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0032] Figure 1 This is a schematic diagram of Scham's Law.

[0033] Figure 2 This is a schematic diagram of the structure of a Sham lens provided in an embodiment of this disclosure;

[0034] Figure 3 The optical path diagram of the Sham lens provided in the embodiments of this disclosure;

[0035] Figure 4 MTF curve of the SAM lens at 25°C for focusing, provided in the embodiments of this disclosure;

[0036] Figure 5 MTF curve of the SAM lens at -10°C when focusing, as provided in the embodiments of this disclosure;

[0037] Figure 6 MTF curve of a SAM lens at 60°C when focusing, provided for an embodiment of this disclosure;

[0038] Figure 7 Field curvature diagram of a Sham lens at 25°C for focusing, provided in an embodiment of this disclosure;

[0039] Figure 8 The distortion diagram of the Sham lens at 25°C provided in the embodiments of this disclosure;

[0040] Figure 9 Field curvature diagram of a Sham lens focusing at -10°C, provided in an embodiment of this disclosure;

[0041] Figure 10 The distortion diagram of the Sham lens when focusing at -10°C is provided in the embodiment of this disclosure;

[0042] Figure 11 Field curvature diagram of a Sham lens at 60°C for focusing, provided in an embodiment of this disclosure;

[0043] Figure 12 The distortion diagram of the Sham lens when focusing at 60°C, provided in the embodiments of this disclosure;

[0044] Figure 13 MTF curve of the SAM lens in the out-of-focus state at 25°C, provided in the embodiments of this disclosure;

[0045] Figure 14 MTF curve of the SAM lens provided in this embodiment of the present disclosure in the out-of-focus state when focusing at -10°C;

[0046] Figure 15 MTF curve of the SAM lens provided in this embodiment of the present disclosure in a defocused state when focusing at 60°C;

[0047] Figure 16 MTF curve of the Sham lens provided in Example 1 of this disclosure;

[0048] Figure 17 MTF curve of the Sham lens provided in Example 2 of this disclosure;

[0049] Figure 18 MTF curve of the Sham lens provided in Example 3 of this disclosure. Detailed Implementation

[0050] Combination Figure 1 According to Schamer's Law, when the extensions of the target plane, the principal plane of the lens, and the detector plane intersect on a single line, a clear image can be formed over the entire field of view of the tilted target. The angles of the optical path must satisfy the following relationship: where α is the angle between the target plane and the lens optical axis, β is the angle between the detector plane and the lens optical axis, f′ is the focal length of the lens, l is the object distance at point D on the optical axis, l' is the image distance at point D on the optical axis, and l' / l is the magnification of the lens.

[0051]

[0052] In related technologies, large-area image sensors have significant advantages in high-precision measurement and complex scene applications. Therefore, it is particularly important to design low-cost, high-imaging-performance lenses while maintaining a large image sensor size.

[0053] In view of this, the present disclosure provides a SAM lens suitable for large target areas, which, while ensuring clear imaging of the target area, uses a smaller number of global surface lenses, thus enabling the lens to simultaneously have low cost and low temperature drift characteristics.

[0054] Embodiments of this disclosure are described in detail below, examples of which are illustrated in the accompanying drawings, wherein the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary and intended to explain this disclosure, and should not be construed as limiting this disclosure.

[0055] Combination Figure 1 This disclosure provides a SAM lens, comprising: a first lens G1, a second lens G2, a third lens G3, a fourth lens G4, a fifth lens G5, a sixth lens G6, and a seventh lens G7 arranged coaxially from the object side to the image side. An aperture stop 40 is provided between the third lens G3 and the fourth lens G4.

[0056] In some embodiments, each lens of the SAM lens is a glass lens. Compared to plastic, glass lenses have higher light transmittance and better imaging results.

[0057] Optical glass comes in many types and possesses stable mechanical and thermal properties, making it suitable for optical structures operating in complex environments. When SAM lenses are used in industrial robots, their working environments are diverse. Using optical glass to fabricate each lens improves the SAM lens's adaptability to various complex environments. Furthermore, using glass lenses for each element helps reduce costs.

[0058] Optical glass can be further divided into crown glass and flint glass based on its refractive index and Abbe number. By combining the two appropriately, chromatic aberration can be eliminated and image quality improved.

[0059] In some embodiments, the lenses of the SAM lens are spherical lenses, which are simple to manufacture and process, and help reduce costs.

[0060] In some embodiments, the incident surface of the first lens G1 is concave, which can converge off-axis beams at large angles while reducing the light path aperture, thereby achieving miniaturization of the optical path structure; it can also meet the imaging requirements of large target surfaces while ensuring the overall size of the lens.

[0061] In some embodiments, an aperture stop 40 is provided between the third lens G3 and the fourth lens G4. The approach surface of the fourth lens G4 facing the aperture stop 40 is concave, so that the side of the fourth lens G4 near the aperture stop 40 bends toward the aperture stop 40, which helps to reduce the angle at which light is incident on the lens surface and correct system aberrations.

[0062] In some embodiments, the fourth lens G4 and the fifth lens G5 are cemented lenses to optimize the large refraction angle brought about by the large aperture stop 40, thereby reducing astigmatism, field curvature, etc. caused by the tilted setting of the CMOS cover glass in the Sham optical path.

[0063] The difference in Abbe number between the fourth lens G4 and the fifth lens G5 is greater than 20. The fourth lens G4 and the fifth lens G5 use different glass materials, which is beneficial for chromatic aberration correction of the beams converging on the image plane, making the Sham lens better suited for use in the short-wavelength band.

[0064] In some embodiments, the first lens G1 has negative optical power, the second lens G2 has positive optical power, the third lens G3 has negative optical power, the fourth lens G4 has negative optical power, the fifth lens G5 has positive optical power, the sixth lens G6 has negative optical power, and the seventh lens G7 has positive optical power.

[0065] Among them, the sixth lens G6 has negative optical power and the seventh lens G7 has positive optical power. By matching the positive and negative light angles, the field curvature and off-axis aberrations are balanced.

[0066] The seventh lens G7 has positive optical power, which can reduce the angle of incidence of the principal ray on the image plane, thereby improving the relative illumination of the system.

[0067] In some embodiments, the difference in refractive index of at least two of the seven lenses in a SAM lens is less than or equal to 0.1, so that the change in refractive index of at least two lenses is small when the temperature changes, which has little impact on the imaging effect. This effectively controls the low temperature drift of the SAM lens, ensuring that the lens can maintain normal resolution in temperatures ranging from -10℃ to 60℃.

[0068] In some embodiments, the seven lenses of the SAM lens are divided into at least two groups, with the difference in refractive index between the lenses in each group being less than 0.1, in order to further improve the low-temperature drift characteristics of the SAM lens.

[0069] For example, regarding the refractive indices of the aforementioned lenses, the refractive index difference between any two of the first lens G1, the second lens G2, and the fifth lens G5 is less than or equal to 0.1, meaning these three lenses have similar refractive indices; similarly, the refractive index difference between any two of the third lens G3, the fourth lens G4, and the seventh lens G7 is less than or equal to 0.05, meaning these three lenses also have similar refractive indices. This configuration helps reduce the impact of temperature changes on the amount of refractive index change, thereby improving the low-temperature drift characteristics of the SAM lens.

[0070] In this embodiment of the disclosure, the parameters of the Sham lens are shown in Table 1.

[0071] Table 1. Parameters of Sham Lens

[0072] 40～60 F2.5~F3.5 60～130

[0073] It should be noted that in the embodiments of this disclosure, when using "~" to define a range, the endpoint values ​​are included. For example, if the focal length f of a SAM lens is 40mm to 60mm, it means that the focal length f of the SAM lens satisfies 40mm ≤ f ≤ 60mm.

[0074] The working distance of the SAM lens is WD 210mm~270mm; the angle α between the optical axis of the SAM lens and the target plane is 18°~25°; the working wavelength of the SAM lens is WL 400nm~480nm; and the magnification of the SAM lens is -0.206.

[0075] In some embodiments, the focal length f of the SAM lens can be 40mm to 50mm; the image-side target diagonal size IMG of the SAM lens is 17mm to 22mm.

[0076] In some embodiments, the focal length f of the Sham lens satisfies the condition 1.8 < f / IMG < 3.0 with respect to the diagonal size IMG of the image target surface.

[0077] In some embodiments, the first lens G1, the second lens G2, and the third lens G3 form a first lens group 10, the fourth lens G4 and the fifth lens G5 form a second lens group 20, and the sixth lens G6 and the seventh lens G7 form a third lens group 30.

[0078] Table 1 above introduces the overall performance parameters of the SAM lens, and Table 2 shows the performance parameters broken down into the three lens groups. In Table 2, the axial spacing refers to the spacing along the optical axis.

[0079] Table 2 Parameters of each lens group of the Sham lens

[0080] First lens group 10 30～50 9～11 Second lens group 20 -75～-55 4～6 Third lens group 30 40～60 —

[0081] For example, the focal length fa of the first lens group is 30mm to 40mm; the focal length fb of the second lens group is -70mm to -50mm; and the focal length fc of the third lens group is 40mm to 55mm.

[0082] The axial distance between the first lens group and the second lens group is 9.5mm to 10.5mm; the axial distance between the second lens group and the third lens group is 4.5mm to 5.5mm.

[0083] In the embodiments of this disclosure, the focal length fa of the first lens group and the focal length f of the SAM lens satisfy 1 < fa / f < 1.7; the focal length fb of the second lens group and the focal length f of the SAM lens satisfy 1 < |fb / f| < 1.8; and the focal length fc of the third lens group and the focal length f of the SAM lens satisfy 0.8 < fc / f < 1.4.

[0084] The axial distance d12 between the first lens group and the second lens group and the axial distance d23 between the second lens group and the third lens group satisfy 1.7 < d12 / d23 < 2.4.

[0085] In this embodiment of the present disclosure, the first lens G1 is a concave-convex lens, the second lens G2 is a biconvex lens, the third lens G3 is a convex-concave lens, the fourth lens G4 is a biconcave lens, the fifth lens G5 is a biconvex lens, the sixth lens G6 is a concave-convex lens, and the seventh lens G7 is a biconvex lens.

[0086] The focal length of each lens is then defined.

[0087] In this embodiment, the focal length f1 of the first lens G1 is -435mm to -345mm; the focal length f2 of the second lens G2 is 35mm to 45mm; the focal length f3 of the third lens G3 is -2660mm to -2120mm; the focal length f4 of the fourth lens G4 is -25mm to -19mm; the focal length f5 of the fifth lens G5 is 60mm to 76mm; the focal length f6 of the sixth lens G6 is -55mm to -43mm; and the focal length f7 of the seventh lens G7 is 23mm to 30mm.

[0088] In this embodiment, the focal length f1 of the first lens G1 and the focal length f of the SAM lens satisfy 7 < |f1 / f| < 10.9; the focal length f2 of the second lens G2 and the focal length f of the SAM lens satisfy 0.7 < f2 / f < 1.2; the focal length f3 of the third lens G3 and the focal length f of the SAM lens satisfy 53 < |f3 / f| < 66.5; the focal length f4 of the fourth lens G4 and the focal length f of the SAM lens satisfy 0.3 < |f4 / f| < 0.7; the focal length f5 of the fifth lens G5 and the focal length f of the SAM lens satisfy 1.2 < f5 / f < 1.9; the focal length f6 of the sixth lens G6 and the focal length f of the SAM lens satisfy 0.8 < |f6 / f| < 1.4; and the focal length f7 of the seventh lens G7 and the focal length f of the SAM lens satisfy 0.4 < f7 / f < 0.8.

[0089] In some embodiments, the focal length f1 of the first lens G1 is -432.76mm to -346.07mm; the focal length f2 of the second lens G2 is 35.85mm to 44.83mm; the focal length f3 of the third lens G3 is -2657.10mm to -2124.87mm; the focal length f4 of the fourth lens G4 is -24.72mm to -19.76mm; the focal length f5 of the fifth lens G5 is 60.29mm to 75.39mm; the focal length f6 of the sixth lens G6 is -54.02mm to -43.20mm; and the focal length f7 of the seventh lens G7 is 23.96mm to 29.960mm.

[0090] The curvature radius of each lens is then defined.

[0091] In this embodiment, the radius of curvature R11 of the incident surface of the first lens G1 is -33mm to -26mm, and the radius of curvature R12 of the exit surface is -38mm to -30mm; the radius of curvature R21 of the incident surface of the second lens G2 is 31mm to 39mm, and the radius of curvature R22 of the exit surface is -180mm to -143mm; the radius of curvature R31 of the incident surface of the third lens G3 is 12mm to 16mm, and the radius of curvature R32 of the exit surface is 10mm to 13mm; the radius of curvature R41 of the incident surface of the fourth lens G4 is -28mm. The radius of curvature of the incident surface of the fifth lens G5 is 9mm to -22mm, and the radius of curvature of the exit surface R42 is 9mm to 13mm; the radius of curvature of the incident surface of the sixth lens G6 is -12mm to -9mm, and the radius of curvature of the exit surface R62 is -23mm to -17mm; the radius of curvature of the incident surface of the seventh lens G7 is 655mm to 820mm, and the radius of curvature of the exit surface R72 is -26mm to -21mm.

[0092] Among them, combined with the appendix Figure 2 The incident surface of a lens is the surface of the lens facing the object; the exit surface of a lens is the surface of the lens facing the image.

[0093] Among them, the radius of curvature R41 of the incident surface of the fourth lens G4 and the radius of curvature R52 of the exit surface of the fifth lens G5 satisfy 0.7 < R41 / R52 < 1.1.

[0094] In some embodiments, the radius of curvature R11 of the incident surface of the first lens G1 is -33.37 mm to -26.68 mm, and the radius of curvature R12 of the exit surface is -38.66 mm to -30.92 mm; the radius of curvature R21 of the incident surface of the second lens G2 is 31.13 mm to 38.92 mm, and the radius of curvature R22 of the exit surface is -179.53 mm to -143.57 mm; the radius of curvature R31 of the incident surface of the third lens G3 is 12.57 mm to 15.72 mm, and the radius of curvature R32 of the exit surface is 10.02 mm to 12.53 mm; the radius of curvature R41 of the incident surface of the fourth lens G4 is -28.32 mm to -33.37 mm. -22.65mm, the radius of curvature R42 of the exit surface is 9.89mm~12.37mm; the radius of curvature R51 of the incident surface of the fifth lens G5 is 9.89mm~12.37mm, and the radius of curvature R52 of the exit surface is -33.48mm~-26.77mm; the radius of curvature R61 of the incident surface of the sixth lens G6 is -11.29mm~-9.54mm, and the radius of curvature R62 of the exit surface is -22.38mm~-17.90mm; the radius of curvature R71 of the incident surface of the seventh lens G7 is 655.53mm~819.72mm, and the radius of curvature R72 of the exit surface is -26.65mm~-21.31mm.

[0095] The center thickness of each lens is defined below.

[0096] In this embodiment, the center thickness GT1 of the first lens G1 is 1.9mm to 2.5mm; the center thickness GT2 of the second lens G2 is 2.4mm to 3.1mm; the center thickness GT3 of the third lens G3 is 5.3mm to 6.7mm; the center thickness GT4 of the fourth lens G4 is 1.3mm to 1.7mm; the center thickness GT5 of the fifth lens G5 is 4.5mm to 5.7mm; the center thickness GT6 of the sixth lens G6 is 1.9mm to 2.5mm; and the center thickness GT7 of the seventh lens G7 is 4.0mm to 5.1mm.

[0097] The center thickness of a lens refers to the thickness of the lens at its center along the optical axis.

[0098] Among them, the center thickness GT4 of the fourth lens G4 and the center thickness GT5 of the fifth lens G5 satisfy 0.2 < GT4 / GT5 < 0.4.

[0099] In some embodiments, the center thickness GT1 of the first lens G1 is 1.97 mm to 2.46 mm; the center thickness GT2 of the second lens G2 is 2.42 mm to 3.02 mm; the center thickness GT3 of the third lens G3 is 5.33 mm to 6.67 mm; the center thickness GT4 of the fourth lens G4 is 1.39 mm to 1.74 mm; the center thickness GT5 of the fifth lens G5 is 4.52 mm to 5.66 mm; the center thickness GT6 of the sixth lens G6 is 1.97 mm to 2.46 mm; and the center thickness GT7 of the seventh lens G7 is 4.07 mm to 5.09 mm.

[0100] The air gap distance between each lens along the optical axis is defined below.

[0101] In this embodiment, the air gap AT1 between the first lens G1 and the second lens G2 along the optical axis is 0.07 mm to 0.11 mm; the air gap AT2 between the second lens G2 and the third lens G3 along the optical axis is 0.07 mm to 0.11 mm; the air gap AT3 between the third lens G3 and the aperture stop 40 along the optical axis is 2.35 mm to 3.00 mm; the air gap AT4 between the aperture stop 40 and the fourth lens G4 along the optical axis is 5.95 mm to 7.50 mm; the fourth lens G4 and the fifth lens G5 are cemented lenses; the air gap AT5 between the fifth lens G5 and the sixth lens G6 along the optical axis is 4.20 mm to 5.30 mm; the air gap AT6 between the sixth lens G6 and the seventh lens G7 along the optical axis is 0.07 mm to 0.11 mm; and the air gap BFL between the seventh lens G7 and the image plane along the optical axis is 20.65 mm to 25.90 mm.

[0102] Among them, the air gap distance AT3 between the third lens G3 and the aperture stop 40 along the optical axis and the air gap distance AT4 between the aperture stop 40 and the fourth lens G4 along the optical axis satisfy 8.3 < AT3 + AT4 < 10.5.

[0103] Among them, the air gap distance BFL between the seventh lens G7 and the image plane along the optical axis satisfies 0.3 < BFL / TTL < 0.5 with respect to the total optical length TTL of the system.

[0104] In some embodiments, the air gap distance AT1 between the first lens G1 and the second lens G2 along the optical axis is 0.08 mm to 0.10 mm; the air gap distance AT2 between the second lens G2 and the third lens G3 along the optical axis is 0.08 mm to 0.10 mm; the air gap distance AT3 between the third lens G3 and the aperture stop 40 along the optical axis is 2.38 mm to 2.97 mm; the air gap distance AT4 between the aperture stop 40 and the fourth lens G4 along the optical axis is 5.98 mm to 7.48 mm; the fourth lens G4 and the fifth lens G5 are cemented lenses; the air gap distance AT5 between the fifth lens G5 and the sixth lens G6 along the optical axis is 4.2 mm to 5.27 mm; the air gap distance AT6 between the sixth lens G6 and the seventh lens G7 along the optical axis is 0.08 mm to 0.10 mm; and the air gap distance BFL between the seventh lens G7 and the image plane along the optical axis is 20.68 mm to 25.85 mm.

[0105] The refractive index and Abbe number of each lens are defined below.

[0106] In this embodiment, the first lens G1 has a refractive index N1 of 1.65–1.7 and an Abbe number V1 of 47–47.5; the second lens G2 has a refractive index N2 of 1.67–1.72 and an Abbe number V2 of 56–56.5; the third lens G3 has a refractive index N3 of 1.8–1.85 and an Abbe number V3 of 42.5–43; the fourth lens G4 has a refractive index N4 of 1.8–1.85 and an Abbe number V4 of 25.2–25.7; the fifth lens G5 has a refractive index N5 of 1.7–1.75 and an Abbe number V5 of 50–50.5; the sixth lens G6 has a refractive index N6 of 1.47–1.52 and an Abbe number V6 of 62–62.5; and the seventh lens G7 has a refractive index N7 of 1.8–1.85 and an Abbe number V7 of 25.2–25.7. This disclosure defines the material properties of each lens by limiting its refractive index and Abbe number.

[0107] Among them, the Abbe number V4 of the fourth lens G4 and the Abbe number V5 of the fifth lens G5 satisfy 24.3 < |V4-V5| < 25.3.

[0108] Regarding the refractive indices of the aforementioned lenses, the maximum difference in refractive indices between the first lens G1, the second lens G2, and the fifth lens G5 is 0.1, indicating that these three lenses have similar refractive indices. Similarly, the maximum difference in refractive indices between the third lens G3, the fourth lens G4, and the seventh lens G7 is 0.05, also indicating that these three lenses have similar refractive indices. This configuration helps to reduce the impact of temperature changes on the amount of refractive index change, thereby improving the low-temperature drift characteristics of the SAM lens.

[0109] Combination Figure 3The optical path diagram shown illustrates how light rays within the field of view (FOV) are imaged onto the image sensor 200 via the Sham lens 100. The diagram demonstrates that, while maintaining lens size and volume, the lens structure is simple and the lens elements are easily manufacturable. The use of seven global surface lenses helps reduce costs.

[0110] The SAM lens of this disclosure is compatible with an image plane size of up to 1.4”, exceeding the image plane size of typical industrial lenses, and can be adapted to ultra-large target surface chips. In other words, the SAM lens of this disclosure can be used with 1.4-inch image sensors and is compatible with ultra-large target surface chips.

[0111] The SAM lens of this disclosure fully controls the external dimensions of the lenses while ensuring that each lens is easy to process, thereby reducing the lens diameter and thus reducing system costs.

[0112] In some embodiments, a cover glass is provided on the light-incident side of the image sensor 200 to protect the image sensor 200. In this embodiment, the cover glass is arranged parallel to the image sensor 200, which facilitates actual assembly and application and saves assembly costs.

[0113] Combination Figures 4 to 6 The figures are MTF (Modulation Transfer Function) curves of the Sham lens in this embodiment of the present disclosure when focusing at 25°C, -10°C and 60°C.

[0114] In the MTF curve, the horizontal axis represents spatial frequency, with units of period / mm (or line pairs / mm), and the vertical axis represents contrast, with a value range of 0-1. Solid and dashed lines represent the meridional and sagittal components of the MTF under different fields of view. The solid line represents the contrast component in the meridional direction, which is perpendicular to the optical axis; the dashed line represents the contrast component in the sagittal direction, which is along the optical axis. Higher curves and closer together indicate higher image quality.

[0115] like Figure 4 As shown in the embodiments of this disclosure, after focusing at 25°C, the modulation transfer function of each field of view of the SAM lens has a contrast greater than 0.5 at a spatial frequency of 60 line pairs / mm; and among -10°C, 25°C and 60°C, the contrast of the modulation transfer function of each field of view at a spatial frequency of 60 line pairs / mm is the greatest when focusing at 25°C.

[0116] Combination Figure 5 and Figure 6 As the temperature varies between -10℃ and 60℃, the attenuation of the vertical axis (i.e., imaging contrast) at a spatial frequency of 60 line pairs / mm in the MTF curve is less than 0.1. Figure 5The contrast ratio of the SAM lens at a spatial frequency of 60 line pairs / mm when focusing at -10℃ is... Figure 6 The contrast difference of the SAM lens at a spatial frequency of 60 line pairs / mm is less than 0.1 when focusing at 60°C, indicating that the SAM lens of this embodiment has low temperature drift characteristics.

[0117] Combination Figure 7 , Figure 9 as well as Figure 11 The figures show the field curvature diagrams of the Sham lens in this embodiment at 25°C, -10°C, and 60°C when focusing. In the field curvature diagrams, the vertical axis represents the field of view, and the horizontal axis is in millimeters. The solid and dashed lines represent the meridional and sagittal components of the field curvature at different wavelengths within the working band. The solid lines represent the meridional field curvature component, which is perpendicular to the optical axis; the dashed lines represent the sagittal field curvature component, which is along the optical axis.

[0118] In conjunction with 7, the SAM lens of this embodiment, after focusing at 25°C, has a field curvature astigmatism value of less than 0.2mm corresponding to the entire field of view of the coaxial optical path, and has good astigmatism correction capability.

[0119] Combination Figure 9 as well as Figure 11 According to the SAM lens of this embodiment, after focusing at 25°C, the change in field curvature astigmatism value is less than 0.05mm as the temperature changes between -10°C and 60°C.

[0120] Combination Figure 8 , Figure 10 as well as Figure 12 The figures show the distortion of the Sham lens according to embodiments of this disclosure when focusing at 25°C, -10°C, and 60°C. In the distortion figures, the vertical axis represents the field of view, and the horizontal axis represents the distortion value. Each curve represents the distortion value at different wavelengths within the operating band.

[0121] Combination Figure 8 The SAM lens of this embodiment has a distortion value of less than 0.2% in the full field of view of the corresponding coaxial optical path after focusing at 25°C, and has a low distortion value.

[0122] Combination Figure 10 and Figure 12 According to the present invention, after focusing at 25°C, the distortion value of the SAM lens remains almost unchanged as the temperature varies between -10°C and 60°C.

[0123] The field curvature diagram and distortion diagram described above demonstrate that the Sham lens of this embodiment possesses low-temperature drift characteristics.

[0124] Combination Figures 13 to 15The figures are MTF (Modulation Transfer Function) curves of the embodiments of this disclosure under defocus conditions of 25°C, -10°C, and 60°C.

[0125] In this graph, the horizontal axis represents the optical back focal displacement in millimeters; the vertical axis represents the contrast, with a range of 0-1. The solid and dashed lines represent the meridional and sagittal components of the MTF under different fields of view.

[0126] Combination Figure 13 After focusing at 25°C, the modulation transfer function of each field of view in the defocus state has the highest contrast when the back focus displacement is 0; and the contrast is greater than 0.5 at 60 line pairs / mm, with the best full field of view imaging effect.

[0127] Combination Figure 14 When focusing at -10℃, the contrast is highest and the image quality is best when the back focus shift is greater than 0 and less than 0.01. Figure 15 When focusing at 60°C, the contrast is maximized and the image quality is best when the back focus shift is less than 0 and greater than 0.01. Combined with... Figure 14 and Figure 15 When the SAM lens images at temperatures ranging from -10℃ to 60℃, the absolute value of the back focus shift change corresponding to the maximum contrast value of the modulation transfer function in each field of view under defocus conditions is less than 0.01, indicating that the lens exhibits low-temperature drift characteristics.

[0128] Based on the above description, the SAM lens of this disclosure is adapted to a large target surface image sensor and uses as few global surface lenses as possible, resulting in a lower cost and low temperature drift characteristics.

[0129] The following are three specific examples of Sham shots.

[0130] Example 1

[0131] In this disclosed example, the working distance WD of the SAM lens is 213mm, the angle α between the target plane and the lens optical axis is 22°, the target plane diagonal size IMG is 17mm, the focal length f is 40mm, and the working wavelength WL is 400nm~480nm.

[0132] In this example, the focal length fa of the first lens group 10 is 31.44 mm; the focal length fb of the second lens group 20 is -54.34 mm; and the focal length fc of the third lens group 30 is 42.25 mm.

[0133] The focal length f1 of the first lens G1 is -346.07mm; the focal length f2 of the second lens G2 is 35.85mm; the focal length f3 of the third lens G3 is -2124.87mm; the focal length f4 of the fourth lens G4 is -19.76mm; the focal length f5 of the fifth lens G5 is 60.29mm; the focal length f6 of the sixth lens G6 is -43.2mm; and the focal length f7 of the seventh lens G7 is 23.96mm.

[0134] The radii of curvature of each lens are as follows: For the first lens G1, the radius of curvature R11 of the incident surface is -26.68 mm, and the radius of curvature R12 of the exit surface is -30.92 mm; for the second lens G2, the radius of curvature R21 of the incident surface is 31.13 mm, and the radius of curvature R22 of the exit surface is -143.57 mm; for the third lens G3, the radius of curvature R31 of the incident surface is 12.57 mm, and the radius of curvature R32 of the exit surface is 10.02 mm; for the fourth lens G4, the radius of curvature R4 of the incident surface is... Lens 1 has an incident surface radius of -22.65mm and an exit surface radius of curvature R42 of 9.89mm; Lens 5 has an incident surface radius of curvature R51 of 9.89mm and an exit surface radius of curvature R52 of -26.77mm; Lens 6 has an incident surface radius of curvature R61 of -9.54mm and an exit surface radius of curvature R62 of -17.90mm; Lens 7 has an incident surface radius of curvature R71 of 655.53mm and an exit surface radius of curvature R72 of -21.31mm.

[0135] The center thickness GT1 of the first lens G1 is 1.97 mm; the center thickness GT2 of the second lens G2 is 2.42 mm; the center thickness GT3 of the third lens G3 is 5.33 mm; the center thickness GT4 of the fourth lens G4 is 1.39 mm; the center thickness GT5 of the fifth lens G5 is 4.52 mm; the center thickness GT6 of the sixth lens G6 is 1.97 mm; and the center thickness GT7 of the seventh lens G7 is 4.07 mm.

[0136] The air gap AT1 between the first lens G1 and the second lens G2 along the optical axis is 0.08 mm; the air gap AT2 between the second lens G2 and the third lens G3 along the optical axis is 0.08 mm; the air gap AT3 between the third lens G3 and the aperture stop 40 along the optical axis is 2.38 mm; the air gap AT4 between the aperture stop 40 and the fourth lens G4 along the optical axis is 5.98 mm; the fourth lens G4 and the fifth lens G5 are cemented lenses; the air gap AT5 between the fifth lens G5 and the sixth lens G6 along the optical axis is 4.22 mm; the air gap AT6 between the sixth lens G6 and the seventh lens G7 along the optical axis is 0.08 mm; the air gap BFL between the seventh lens G7 and the image plane along the optical axis is 20.68 mm.

[0137] The first lens G1 has a refractive index N1 of 1.67 and an Abbe number V1 of 47.3; the second lens G2 has a refractive index N2 of 1.70 and an Abbe number V2 of 56.2; the third lens G3 has a refractive index N3 of 1.83 and an Abbe number V3 of 42.7; the fourth lens G4 has a refractive index N4 of 1.81 and an Abbe number V4 of 25.5; the fifth lens G5 has a refractive index N5 of 1.72 and an Abbe number V5 of 50.3; the sixth lens G6 has a refractive index N6 of 1.50 and an Abbe number V6 of 62.1; and the seventh lens G7 has a refractive index N7 of 1.81 and an Abbe number V7 of 25.5.

[0138] Combination Figure 16 The optical lens in this example has a contrast ratio greater than or equal to 0.5 at a spatial frequency of 60 cycles / mm across the entire field of view, indicating high resolution.

[0139] Example 2

[0140] In this disclosed example, the working distance WD of the SAM lens is 240mm, the angle α between the target plane and the lens optical axis is 22°, the target plane diagonal size IMG is 19mm, the focal length f is 45mm, and the working wavelength WL is 400nm~480nm.

[0141] In the example disclosed herein, the focal length fa of the first lens group 10 is 35.38 mm; the focal length fb of the second lens group 20 is -61.35 mm; and the focal length fc of the third lens group 30 is 47.60 mm.

[0142] The focal length f1 of the first lens G1 is -389.48mm; the focal length f2 of the second lens G2 is 40.35mm; the focal length f3 of the third lens G3 is -2391.39mm; the focal length f4 of the fourth lens G4 is -22.24mm; the focal length f5 of the fifth lens G5 is 67.85mm; the focal length f6 of the sixth lens G6 is -48.62mm; and the focal length f7 of the seventh lens G7 is 26.96mm.

[0143] The radii of curvature of each lens are as follows: For the first lens G1, the radius of curvature R11 of the incident surface is -30.03 mm, and the radius of curvature R12 of the exit surface is -34.80 mm; for the second lens G2, the radius of curvature R21 of the incident surface is 35.03 mm, and the radius of curvature R22 of the exit surface is -161.58 mm; for the third lens G3, the radius of curvature R31 of the incident surface is 14.15 mm, and the radius of curvature R32 of the exit surface is 11.28 mm; for the fourth lens G4, the radius of curvature R41 of the incident surface is... The radius of curvature of the incident surface of the fifth lens G5 is -25.49mm, and the radius of curvature of the exit surface R42 is 11.13mm; the radius of curvature of the incident surface of the sixth lens G6 is -10.73mm, and the radius of curvature of the exit surface R62 is -20.15mm; the radius of curvature of the incident surface of the seventh lens G7 is 737.75mm, and the radius of curvature of the exit surface R72 is -23.99mm.

[0144] The center thickness GT1 of the first lens G1 is 2.21 mm; the center thickness GT2 of the second lens G2 is 2.72 mm; the center thickness GT3 of the third lens G3 is 6.00 mm; the center thickness GT4 of the fourth lens G4 is 1.57 mm; the center thickness GT5 of the fifth lens G5 is 5.09 mm; the center thickness GT6 of the sixth lens G6 is 2.21 mm; and the center thickness GT7 of the seventh lens G7 is 4.58 mm.

[0145] The air gap AT1 between the first lens G1 and the second lens G2 along the optical axis is 0.09 mm; the air gap AT2 between the second lens G2 and the third lens G3 along the optical axis is 0.09 mm; the air gap AT3 between the third lens G3 and the aperture stop 40 along the optical axis is 2.67 mm; the air gap AT4 between the aperture stop 40 and the fourth lens G4 along the optical axis is 6.73 mm; the fourth lens G4 and the fifth lens G5 are cemented lenses; the air gap AT5 between the fifth lens G5 and the sixth lens G6 along the optical axis is 4.75 mm; the air gap AT6 between the sixth lens G6 and the seventh lens G7 along the optical axis is 0.09 mm; the air gap BFL between the seventh lens G7 and the image plane along the optical axis is 23.27 mm.

[0146] The first lens G1 has a refractive index N1 of 1.67 and an Abbe number V1 of 47.3; the second lens G2 has a refractive index N2 of 1.70 and an Abbe number V2 of 56.2; the third lens G3 has a refractive index N3 of 1.83 and an Abbe number V3 of 42.7; the fourth lens G4 has a refractive index N4 of 1.81 and an Abbe number V4 of 25.5; the fifth lens G5 has a refractive index N5 of 1.72 and an Abbe number V5 of 50.3; the sixth lens G6 has a refractive index N6 of 1.50 and an Abbe number V6 of 62.1; and the seventh lens G7 has a refractive index N7 of 1.81 and an Abbe number V7 of 25.5.

[0147] Combination Figure 17 The optical lens in this example has a contrast ratio greater than or equal to 0.5 at a spatial frequency of 60 cycles / mm across the entire field of view, indicating high resolution.

[0148] Example 3

[0149] In this disclosed example, the working distance WD of the SAM lens is 266mm, the angle α between the target plane and the lens optical axis is 22°, the target plane diagonal size IMG is 21.2mm, the focal length f is 50mm, and the working wavelength WL is 400nm~480nm.

[0150] In the example disclosed herein, the focal length fa of the first lens group 10 is 39.32 mm, the focal length fb of the second lens group 20 is -68.17 mm, and the focal length fc of the third lens group 30 is 52.89 mm.

[0151] The focal length f1 of the first lens G1 is -432.76mm; the focal length f2 of the second lens G2 is 44.83mm; the focal length f3 of the third lens G3 is -2657.10mm; the focal length f4 of the fourth lens G4 is -24.72mm; the focal length f5 of the fifth lens G5 is 75.39mm; the focal length f6 of the sixth lens G6 is -54.02mm; and the focal length f7 of the seventh lens G7 is 29.96mm.

[0152] The radii of curvature of each lens are as follows: For the first lens G1, the radius of curvature R11 of the incident surface is -33.37 mm, and the radius of curvature R12 of the exit surface is -38.66 mm; for the second lens G2, the radius of curvature R21 of the incident surface is 38.92 mm, and the radius of curvature R22 of the exit surface is -179.53 mm; for the third lens G3, the radius of curvature R31 of the incident surface is 15.72 mm, and the radius of curvature R32 of the exit surface is 12.53 mm; for the fourth lens G4, the radius of curvature R41 of the incident surface is... The radius of curvature of the incident surface of the fifth lens G5 is -28.32mm, and the radius of curvature of the exit surface R42 is 12.37mm; the radius of curvature of the incident surface of the sixth lens G6 is -11.92mm, and the radius of curvature of the exit surface R62 is -22.38mm; the radius of curvature of the incident surface of the seventh lens G7 is 819.72mm, and the radius of curvature of the exit surface R72 is -26.65mm.

[0153] The center thickness GT1 of the first lens G1 is 2.46 mm; the center thickness GT2 of the second lens G2 is 3.02 mm; the center thickness GT3 of the third lens G3 is 6.67 mm; the center thickness GT4 of the fourth lens G4 is 1.74 mm; the center thickness GT5 of the fifth lens G5 is 5.66 mm; the center thickness GT6 of the sixth lens G6 is 2.46 mm; and the center thickness GT7 of the seventh lens G7 is 5.09 mm.

[0154] The air gap AT1 between the first lens G1 and the second lens G2 along the optical axis is 0.10 mm; the air gap AT2 between the second lens G2 and the third lens G3 along the optical axis is 0.10 mm; the air gap AT3 between the third lens G3 and the aperture stop 40 along the optical axis is 2.97 mm; the air gap AT4 between the aperture stop 40 and the fourth lens G4 along the optical axis is 7.48 mm; the fourth lens G4 and the fifth lens G5 are cemented lenses; the air gap AT5 between the fifth lens G5 and the sixth lens G6 along the optical axis is 5.27 mm; the air gap AT6 between the sixth lens G6 and the seventh lens G7 along the optical axis is 0.10 mm; the air gap BFL between the seventh lens G7 and the image plane along the optical axis is 25.85 mm.

[0155] The first lens G1 has a refractive index N1 of 1.67 and an Abbe number V1 of 47.3; the second lens G2 has a refractive index N2 of 1.70 and an Abbe number V2 of 56.2; the third lens G3 has a refractive index N3 of 1.83 and an Abbe number V3 of 42.7; the fourth lens G4 has a refractive index N4 of 1.81 and an Abbe number V4 of 25.5; the fifth lens G5 has a refractive index N5 of 1.72 and an Abbe number V5 of 50.3; the sixth lens G6 has a refractive index N6 of 1.50 and an Abbe number V6 of 62.1; and the seventh lens G7 has a refractive index N7 of 1.81 and an Abbe number V7 of 25.5.

[0156] Combination Figure 18 The optical lens in this example has a contrast ratio greater than 0.48 at a spatial frequency of 60 cycles / mm across the entire field of view, demonstrating high resolution.

[0157] This disclosure also provides an electronic device that includes the optical lens described in the above embodiments. The structure, function, and effects of the optical lens provided in this embodiment are the same as those in the above embodiments, and specific details can be found in the above embodiments, which will not be repeated here.

[0158] In some embodiments of this disclosure, the electronic device is a camera. The camera may be a monocular camera, a binocular camera, or a 3D camera, etc.

[0159] In the above description, the use of terms such as "one embodiment," "some embodiments," "example," "specific example," or "some examples," etc., refers to a specific feature, structure, material, or characteristic described in connection with that embodiment or example, which is included in at least one embodiment or example of this disclosure. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples. Moreover, without contradiction, those skilled in the art can combine and integrate the different embodiments or examples described in this specification, as well as the features of different embodiments or examples.

[0160] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of this disclosure, and are not intended to limit them. Although this disclosure has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features therein. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of this disclosure.

Claims

1. A Sham lens, characterized in that, include: A first lens, a second lens, a third lens, a fourth lens, a fifth lens, a sixth lens, and a seventh lens are arranged coaxially from the object side to the image side; the fourth lens and the fifth lens are cemented lenses; the incident surface of the first lens is concave. An aperture stop is provided between the third lens and the fourth lens, and the ingress surface of the fourth lens facing the aperture stop is concave. The difference in refractive index of at least two of the seven lenses in the Sham lens is less than or equal to 0.

1. The first lens has negative optical power, the second lens has positive optical power, the third lens has negative optical power, the fourth lens has negative optical power, the fifth lens has positive optical power, the sixth lens has negative optical power, and the seventh lens has positive optical power. The focal length f1 of the first lens and the focal length f of the SAM lens satisfy 7 < |f1 / f| < 10.9; the focal length f2 of the second lens and the focal length f of the SAM lens satisfy 0.7 < f2 / f < 1.2; the focal length f3 of the third lens and the focal length f of the SAM lens satisfy 53 < |f3 / f| < 66.5; the focal length f4 of the fourth lens and the focal length f of the SAM lens satisfy 0.3 < |f4 / f| < 0.7; the focal length f5 of the fifth lens and the focal length f of the SAM lens satisfy 1.2 < f5 / f < 1.9; the focal length f6 of the sixth lens and the focal length f of the SAM lens satisfy 0.8 < |f6 / f| < 1.4; the focal length f7 of the seventh lens and the focal length f of the SAM lens satisfy 0.4 < f7 / f < 0.

8. The Sham lens has seven lenses, and the object side of the first lens is concave and the image side is convex; the object side of the second lens is convex and the image side is convex; the object side of the third lens is convex and the image side is concave; the object side of the fourth lens is concave and the image side is concave; the object side of the fifth lens is convex and the image side is convex; the object side of the sixth lens is concave and the image side is convex; and the object side of the seventh lens is convex and the image side is convex.

2. The Sham lens according to claim 1, characterized in that, The difference in refractive index between any two of the third lens, the fourth lens, and the seventh lens is less than or equal to 0.

05.

3. The Sham lens according to claim 1, characterized in that, The difference in Abbe number between the fourth lens and the fifth lens is greater than 20.

4. The Sham lens according to claim 1, characterized in that, The focal length f1 of the first lens is -435mm to -345mm; the focal length f2 of the second lens is 35mm to 45mm; the focal length f3 of the third lens is -2660mm to -2120mm; the focal length f4 of the fourth lens is -25mm to -19mm; the focal length f5 of the fifth lens is 60mm to 76mm; the focal length f6 of the sixth lens is -55mm to -43mm; and the focal length f7 of the seventh lens is 23mm to 30mm.

5. The Sham lens according to claim 1, characterized in that, The first lens has an incident surface radius of curvature R11 of -33mm to -26mm and an exit surface radius of curvature R12 of -38mm to -30mm; the second lens has an incident surface radius of curvature R21 of 31mm to 39mm and an exit surface radius of curvature R22 of -180mm to -143mm; the third lens has an incident surface radius of curvature R31 of 12mm to 16mm and an exit surface radius of curvature R32 of 10mm to 13mm; the fourth lens has an incident surface radius of curvature R41 of -28mm to - The radius of curvature of the incident surface of the fifth lens is 22mm, and the radius of curvature of the exit surface R42 is 9mm to 13mm; the radius of curvature of the incident surface of the sixth lens is 9mm to 13mm, and the radius of curvature of the exit surface R52 is -33mm to -26mm; the radius of curvature of the incident surface of the sixth lens is -12mm to -9mm, and the radius of curvature of the exit surface R62 is -23mm to -17mm; the radius of curvature of the incident surface of the seventh lens is 655mm to 820mm, and the radius of curvature of the exit surface R72 is -26mm to -21mm.

6. The Sham lens according to claim 1, characterized in that, The center thickness GT1 of the first lens is 1.9mm to 2.5mm; the center thickness GT2 of the second lens is 2.4mm to 3.1mm; the center thickness GT3 of the third lens is 5.3mm to 6.7mm; the center thickness GT4 of the fourth lens is 1.3mm to 1.7mm; the center thickness GT5 of the fifth lens is 4.5mm to 5.7mm; the center thickness GT6 of the sixth lens is 1.9mm to 2.5mm; and the center thickness GT7 of the seventh lens is 4.0mm to 5.1mm.

7. The Sham lens according to claim 1, characterized in that, The air gap distance AT1 between the first lens and the second lens along the optical axis is 0.07mm to 0.11mm; the air gap distance AT2 between the second lens and the third lens along the optical axis is 0.07mm to 0.11mm; the air gap distance AT3 between the third lens and the aperture stop along the optical axis is 2.35mm to 3.00mm; the air gap distance AT4 between the aperture stop and the fourth lens along the optical axis is 5.95mm to 7.50mm; the fourth lens and the fifth lens are cemented lenses; the air gap distance AT5 between the fifth lens and the sixth lens along the optical axis is 4.20mm to 5.30mm; the air gap distance AT6 between the sixth lens and the seventh lens along the optical axis is 0.07mm to 0.11mm; and the air gap distance BFL between the seventh lens and the image plane along the optical axis is 20.65mm to 25.90mm.

8. The Sham lens according to claim 1, characterized in that, The first lens has a refractive index N1 of 1.65–1.7 and an Abbe number V1 of 47–47.5; the second lens has a refractive index N2 of 1.67–1.72 and an Abbe number V2 of 56–56.5; the third lens has a refractive index N3 of 1.8–1.85 and an Abbe number V3 of 42.5–43; the fourth lens has a refractive index N4 of 1.8–1.85 and an Abbe number V4 of 25.2–25.7; the fifth lens has a refractive index N5 of 1.7–1.75 and an Abbe number V5 of 50–50.5; the sixth lens has a refractive index N6 of 1.47–1.52 and an Abbe number V6 of 62–62.5; and the seventh lens has a refractive index N7 of 1.8–1.85 and an Abbe number V7 of 25.2–25.

7.

9. The Sham lens according to claim 1, characterized in that, The radius of curvature R41 of the incident surface of the fourth lens and the radius of curvature R52 of the exit surface of the fifth lens satisfy 0.7 < R41 / R52 < 1.

1. The center thickness GT4 of the fourth lens and the center thickness GT5 of the fifth lens satisfy 0.2 < GT4 / GT5 < 0.4; The Abbe number V4 of the fourth lens and the Abbe number V5 of the fifth lens satisfy 24.3 < |V4-V5| < 25.

3.

10. The Sham lens according to any one of claims 1-9, characterized in that, The focal length of the SAM lens is 40mm to 60mm; the aperture number of the SAM lens is F2.5 to 3.5; the field of view (FOV) of the SAM lens is 60mm to 130mm; the working distance (WD) of the SAM lens is 210mm to 270mm; the angle α between the optical axis of the SAM lens and the target plane is 18° to 25°; the working wavelength (WL) of the SAM lens is 400nm to 480nm; and the magnification of the SAM lens is -0.

206.

11. The Sham lens according to any one of claims 1-9, characterized in that, The first lens, the second lens, and the third lens form a first lens group, wherein the focal length fa of the first lens group is 30mm to 50mm. The fourth lens and the fifth lens form a second lens group, and the focal length fb of the second lens group is -75mm to -55mm. The sixth lens and the seventh lens form a third lens group, and the focal length fc of the third lens group is 40mm to 60mm. The axial distance between the first lens group and the second lens group is 9mm to 11mm; the axial distance between the second lens group and the third lens group is 4mm to 6mm.

12. The Sham lens according to claim 11, characterized in that, The focal length fa of the first lens group and the focal length f of the Sham lens satisfy 1 < fa / f < 1.7; the focal length fb of the second lens group and the focal length f of the Sham lens satisfy 1 < |fb / f| < 1.8; the focal length fc of the third lens group and the focal length f of the Sham lens satisfy 0.8 < fc / f < 1.

4. The axial distance d12 between the first lens group and the second lens group and the axial distance d23 between the second lens group and the third lens group satisfy 1.7 < d12 / d23 < 2.

4.

13. The Sham lens according to any one of claims 1-9, characterized in that, After focusing at 25°C, the modulation transfer function of the SAM lens has a contrast greater than 0.5 at a spatial frequency of 60 line pairs / mm for each field of view. After imaging at temperatures ranging from -10℃ to 60℃, the modulation transfer function of the SAM lens exhibits a contrast attenuation of less than 0.1 at a spatial frequency of 60 line pairs / mm for each field of view. When the SAM lens is focused at 25°C, the field curvature astigmatism value of the corresponding coaxial optical path full field of view is less than 0.2mm. The distortion value of the Sham lens is less than 0.2% across the entire field of view in the corresponding coaxial optical path; After imaging at temperatures ranging from -10℃ to 60℃, the change in field curvature astigmatism across the entire field of view of the coaxial optical path using the SAM lens is less than 0.05mm.

14. The Sham lens according to any one of claims 1-9, characterized in that, After focusing at 25°C, the modulation transfer function of each field of view in the defocus state has the maximum contrast when the back focus displacement is 0, and the contrast is greater than 0.

5. After imaging at temperatures ranging from -10℃ to 60℃, the absolute value of the back focus displacement change corresponding to the maximum contrast value of the modulation transfer function in each field of view under defocus conditions is less than 0.

01.

15. The Sham lens according to any one of claims 1-9, characterized in that, Each lens element of the Sham lens is a glass lens, and each lens element of the Sham lens is a spherical lens.

16. An electronic device, characterized in that, Includes the Sham lens as described in any one of claims 1-15.

17. The electronic device according to claim 16, characterized in that, The electronic device is a camera.

Images